linux/drivers/clk/st/clk-flexgen.c

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/*
* clk-flexgen.c
*
* Copyright (C) ST-Microelectronics SA 2013
* Author: Maxime Coquelin <maxime.coquelin@st.com> for ST-Microelectronics.
* License terms: GNU General Public License (GPL), version 2 */
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/of.h>
#include <linux/of_address.h>
struct flexgen {
struct clk_hw hw;
/* Crossbar */
struct clk_mux mux;
/* Pre-divisor's gate */
struct clk_gate pgate;
/* Pre-divisor */
struct clk_divider pdiv;
/* Final divisor's gate */
struct clk_gate fgate;
/* Final divisor */
struct clk_divider fdiv;
};
#define to_flexgen(_hw) container_of(_hw, struct flexgen, hw)
static int flexgen_enable(struct clk_hw *hw)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *pgate_hw = &flexgen->pgate.hw;
struct clk_hw *fgate_hw = &flexgen->fgate.hw;
pgate_hw->clk = hw->clk;
fgate_hw->clk = hw->clk;
clk_gate_ops.enable(pgate_hw);
clk_gate_ops.enable(fgate_hw);
pr_debug("%s: flexgen output enabled\n", __clk_get_name(hw->clk));
return 0;
}
static void flexgen_disable(struct clk_hw *hw)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *fgate_hw = &flexgen->fgate.hw;
/* disable only the final gate */
fgate_hw->clk = hw->clk;
clk_gate_ops.disable(fgate_hw);
pr_debug("%s: flexgen output disabled\n", __clk_get_name(hw->clk));
}
static int flexgen_is_enabled(struct clk_hw *hw)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *fgate_hw = &flexgen->fgate.hw;
fgate_hw->clk = hw->clk;
if (!clk_gate_ops.is_enabled(fgate_hw))
return 0;
return 1;
}
static u8 flexgen_get_parent(struct clk_hw *hw)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *mux_hw = &flexgen->mux.hw;
mux_hw->clk = hw->clk;
return clk_mux_ops.get_parent(mux_hw);
}
static int flexgen_set_parent(struct clk_hw *hw, u8 index)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *mux_hw = &flexgen->mux.hw;
mux_hw->clk = hw->clk;
return clk_mux_ops.set_parent(mux_hw, index);
}
static inline unsigned long
clk_best_div(unsigned long parent_rate, unsigned long rate)
{
return parent_rate / rate + ((rate > (2*(parent_rate % rate))) ? 0 : 1);
}
static long flexgen_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
unsigned long div;
/* Round div according to exact prate and wished rate */
div = clk_best_div(*prate, rate);
if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
*prate = rate * div;
return rate;
}
return *prate / div;
}
unsigned long flexgen_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
unsigned long mid_rate;
pdiv_hw->clk = hw->clk;
fdiv_hw->clk = hw->clk;
mid_rate = clk_divider_ops.recalc_rate(pdiv_hw, parent_rate);
return clk_divider_ops.recalc_rate(fdiv_hw, mid_rate);
}
static int flexgen_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct flexgen *flexgen = to_flexgen(hw);
struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
unsigned long primary_div = 0;
int ret = 0;
pdiv_hw->clk = hw->clk;
fdiv_hw->clk = hw->clk;
primary_div = clk_best_div(parent_rate, rate);
clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate);
ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * primary_div);
return ret;
}
static const struct clk_ops flexgen_ops = {
.enable = flexgen_enable,
.disable = flexgen_disable,
.is_enabled = flexgen_is_enabled,
.get_parent = flexgen_get_parent,
.set_parent = flexgen_set_parent,
.round_rate = flexgen_round_rate,
.recalc_rate = flexgen_recalc_rate,
.set_rate = flexgen_set_rate,
};
struct clk *clk_register_flexgen(const char *name,
const char **parent_names, u8 num_parents,
void __iomem *reg, spinlock_t *lock, u32 idx,
unsigned long flexgen_flags) {
struct flexgen *fgxbar;
struct clk *clk;
struct clk_init_data init;
u32 xbar_shift;
void __iomem *xbar_reg, *fdiv_reg;
fgxbar = kzalloc(sizeof(struct flexgen), GFP_KERNEL);
if (!fgxbar)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &flexgen_ops;
init.flags = CLK_IS_BASIC | flexgen_flags;
init.parent_names = parent_names;
init.num_parents = num_parents;
xbar_reg = reg + 0x18 + (idx & ~0x3);
xbar_shift = (idx % 4) * 0x8;
fdiv_reg = reg + 0x164 + idx * 4;
/* Crossbar element config */
fgxbar->mux.lock = lock;
fgxbar->mux.mask = BIT(6) - 1;
fgxbar->mux.reg = xbar_reg;
fgxbar->mux.shift = xbar_shift;
fgxbar->mux.table = NULL;
/* Pre-divider's gate config (in xbar register)*/
fgxbar->pgate.lock = lock;
fgxbar->pgate.reg = xbar_reg;
fgxbar->pgate.bit_idx = xbar_shift + 6;
/* Pre-divider config */
fgxbar->pdiv.lock = lock;
fgxbar->pdiv.reg = reg + 0x58 + idx * 4;
fgxbar->pdiv.width = 10;
/* Final divider's gate config */
fgxbar->fgate.lock = lock;
fgxbar->fgate.reg = fdiv_reg;
fgxbar->fgate.bit_idx = 6;
/* Final divider config */
fgxbar->fdiv.lock = lock;
fgxbar->fdiv.reg = fdiv_reg;
fgxbar->fdiv.width = 6;
fgxbar->hw.init = &init;
clk = clk_register(NULL, &fgxbar->hw);
if (IS_ERR(clk))
kfree(fgxbar);
else
pr_debug("%s: parent %s rate %u\n",
__clk_get_name(clk),
__clk_get_name(clk_get_parent(clk)),
(unsigned int)clk_get_rate(clk));
return clk;
}
static const char ** __init flexgen_get_parents(struct device_node *np,
int *num_parents)
{
const char **parents;
int nparents, i;
nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
if (WARN_ON(nparents <= 0))
return NULL;
parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);
if (!parents)
return NULL;
for (i = 0; i < nparents; i++)
parents[i] = of_clk_get_parent_name(np, i);
*num_parents = nparents;
return parents;
}
void __init st_of_flexgen_setup(struct device_node *np)
{
struct device_node *pnode;
void __iomem *reg;
struct clk_onecell_data *clk_data;
const char **parents;
int num_parents, i;
spinlock_t *rlock = NULL;
unsigned long flex_flags = 0;
pnode = of_get_parent(np);
if (!pnode)
return;
reg = of_iomap(pnode, 0);
if (!reg)
return;
parents = flexgen_get_parents(np, &num_parents);
if (!parents)
return;
clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
if (!clk_data)
goto err;
clk_data->clk_num = of_property_count_strings(np ,
"clock-output-names");
if (clk_data->clk_num <= 0) {
pr_err("%s: Failed to get number of output clocks (%d)",
__func__, clk_data->clk_num);
goto err;
}
clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *),
GFP_KERNEL);
if (!clk_data->clks)
goto err;
rlock = kzalloc(sizeof(spinlock_t), GFP_KERNEL);
if (!rlock)
goto err;
for (i = 0; i < clk_data->clk_num; i++) {
struct clk *clk;
const char *clk_name;
if (of_property_read_string_index(np, "clock-output-names",
i, &clk_name)) {
break;
}
/*
* If we read an empty clock name then the output is unused
*/
if (*clk_name == '\0')
continue;
clk = clk_register_flexgen(clk_name, parents, num_parents,
reg, rlock, i, flex_flags);
if (IS_ERR(clk))
goto err;
clk_data->clks[i] = clk;
}
kfree(parents);
of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
return;
err:
if (clk_data)
kfree(clk_data->clks);
kfree(clk_data);
kfree(parents);
kfree(rlock);
}
CLK_OF_DECLARE(flexgen, "st,flexgen", st_of_flexgen_setup);